In the field of musical performance, percussive instruments comprising of various types and styles of drums are used to communicate the rhythm of a musical piece being played by producing a variety of audible beats on command by a percussionist or drummer. The present invention relates to an acoustic drum head tuning system. More precisely, the present invention relates to a pneumatic system that operates an inclusive distensible annular bladder that is positioned a continuous 360° at the outer periphery of a drum head whereby increasing, maintaining or reducing the regulated pressure of a compressed gas contained within the bladder uniformly increases, maintains or reduces bladder displacement, which uniformly increases, maintains or reduces applied tension evenly on all points of the head playing surface which thereby produces an acoustically clear and pleasant sounding uniform pitch that is easily and uniformly raised, maintained or lowered, at any time at the drummer's command, even while performing a musical piece.
A more detailed examination of the prior art and conventional percussive instruments and drums reveals that commonly there exists an array of non-uniform mechanical irregularities in drum head support systems. Non-uniform mechanical irregularities produce a non-uniform resonation of a drum head when it is struck. Non-uniform resonation of a drum head produces sound that includes inharmonic dissonant acoustical overtones and mixed sour pitches that are unpleasant sounding to the human ear. The unpleasant sound produced is similar to that which is heard from stringed musical instrument such as a violin being played when it is out of tune.
Further, when properly tuned the sound produced from a drum will carry a specific pitch or note that is found on the musical scale. Percussionists and drummers continually strive to tune all drum heads as close as possible to uniformly resonating at specific pitches so each drum head will harmonize or sound in concert with other drum heads as well as with other musical instruments involved in a particular musical performance.
In any conventional percussion instrument such as a snare drum, tom, or bass drum, as well as in timpani, timbale, conga or djembe, the drum consists of a hollow, often cylindrical shell with or without openings that are commonly located at opposing ends. One or both openings are commonly covered by a drum head made from a thin polymer film or skin. Each drum head is commonly retained against the end, or sound edge, of the hollow cylindrical shell by a metal rim. Commonly, the drum head includes a rigid circular hoop at its outermost periphery which extends over the end or sound edge of the shell providing a surface for the rim to secure and move the hoop so that the drum head is tensioned more or less over the sound edge. The rim is secured in place and has its tension against the hoop adjusted by a plurality of threaded tension rods evenly spaced around the rim that thread into correlating lugs that are fixed to the outside of the shell. Tension is applied either tighter or looser with a special drum key used to adjust head tension by hand, doing so in small alternating incremental adjustments to each of the tension rods. A higher pitch is produced by the drum head in the area nearest to each individual tension rod as it is tightened or advanced. Conversely, a lower pitch is produced by the drum head in the area nearest to each individual tension rod as it is loosened or retracted.
Conventional drums commonly consist of one or two opposing drum heads. The drum head located closest to the drummer and most commonly played is referred to as a batter head since it is the one that is commonly struck by an object, such as a drum stick, mallet or beater. The opposing drum head located furthest from the drummer is referred to as a resonating drum head which resonates producing a combined audible sound as it is impacted by the sound waves that are generated by the batter head. In such a case, when the batter head is struck, both drum heads resonate simultaneously producing a harmonic or inharmonic sound. Occasionally, a batter head is used on a drum without the use of an opposing resonating drum head to produce a flatter sound with a lesser depth of resonance.
The major problem with conventional acoustic drum head tuning occurs as percussionists and drummers strive for clear acoustic drum head tuning to specific pitches, achieving this continually evades them due to a combination of mechanical and atmospheric factors. Conventional acoustic drum head tuning has always been a time consuming process that is viewed by many as a highly skilled art. Continual efforts are made by drummers to tension heads uniformly by hand and by ear to minimize the degree of non-uniform head tension, non-uniform head resonation, and the presence of unpleasant inharmonic dissonant acoustical overtones and mixed sour pitches that are undesirable to the human ear when the head is struck. Clear sounding, uniformly tensioned and pitched conventional drum head tuning requires an advanced level of experience, skill and musical talent that involves tapping the drum head near each tension rod to hear the sound generated in that area as compared to the areas adjacent to the other tension rods. The drummer must first tap the head, listen and then tighten or loosen each tension rod using a special drum key in order to approach a desired pitch that is closer to matching the others throughout the drum head. While adjusting one tension rod, the adjustment has an influence on the settings of all of the other tension rods on the same head. Drum head tuning to match a desired pitch requires many minor incremental adjustments to every tension rod on each drum head. Any desired change in the pitch of any drum head, once again requires many minor incremental readjustments to every tension rod on each drum head.
In addition to this tedious process, when a drum has two heads, the bottom resonant head must be tuned to precisely correspond with the top batter head. The precise matching of all tensions, all tones and pitch that is produced by the top batter head, with all tensions, all tones and pitch that is produced by the opposing bottom resonant head on the same drum is nearly impossible when using the conventional method of hand tuning. Bottom drum head tuning is often neglected since they are typically located away from the drummer in a position where access is limited.
It is also common to desire that the pitch of each drum head will harmonize in concert with the pitches of other drums in the same set, as well as with other musical instruments used of a particular musical style or performance.
Further, where marching bands or drum corps will commonly use any number of the same sizes and style of drum in marching lines or formations, it is common practice to attempt matching all tensions, all tones and all pitches of all heads.
Advanced drummers commonly would like the ability to bend or change the notes or precise pitches of their drum heads fast and easy, or in real-time, while creatively playing, in a fashion similar to that of a string or wind instrument such as a guitar or saxophone. Conventional drum head tuning cannot be accomplished fast and easy, between musical pieces or in real-time while one is playing the drums.
Conventional drums are mechanical devices that consist of manufactured parts and hardware which are made with manufacturing tolerances that combine to produce negative influences on uniform head tension, head resonance and the final sound quality of a drum head. Poor sound quality is especially evident in cheaply manufactured drums; old used drums with bent rims, warped shells, or disfigured shell sound edges or dented worn-out heads. Also, changes in atmospheric conditions local to the drum, including; temperature, relative humidity and barometric pressure causes changes to head tension. Mechanical imperfections of conventional drums, plus varying atmospheric conditions local to the drum all combine to have negative influencing effects on drum head tuning and the quality of sound produced.
One development in the concept of quick-tuning drums is called a Roto-Tom. This type of instrument usually has only one batter drum head held against a cast metal ring by a rim, which rim pulls the head tightly against the metal ring. Unique to this design are the tension rods spaced around the hoop, because when the entire drum is rotated, the tension rods collectively tighten and pressure the drum head against the ring, still having individually set tension rods. As a result, rotating the drum in one direction generally tightens the head tension and counter-rotating the drum generally decreases the head tension. These are specially made one-headed drums having no shell or opposing resonating drum head which will produce a flatter sound with less depth of resonance.
One method of quickly changing the pitch of drums is disclosed in U.S. Pat. No. 3,590,680 to Carnes et al. Carnes discloses an apparatus for changing the pitch of a drum by conducting pressurized gas into the interior of the drum. Thus, when the drum is pressurized, the pitch is raised; lowering the gas pressure lowers the pitch. However, conventional drums are not air-tight pressure-rated vessels. Make-up air would be needed to maintain any pitch due to the continual air leakage and excessive internal pressures inside any conventional drum will cause it to explode.
There have been other attempts at using air to affect the pitch of a drum. For instance, U.S. Pat. No. 3,240,096 to Sloan discloses a pneumatic drum head tightener. Sloan uses an annular vellum, inflated with air, which is stretched around the circumference of the drum and acts somewhat as a shock absorber. This device has no practical means for simple application to existing conventional drums.
U.S. Pat. No. 3,541,913 to Severino discloses an inflated tube that is incorporated into the outside shell of a drum in order to facilitate easy replacement of the drum head. When the captive tube is inflated, it pulls down a collar which acts on the drum head to tighten or loosen the same. This device, however, requires specialized and complicated hardware in order for the inflatable tube to operate properly. This device has no practical means for simple application to existing conventional drums.
Another example of pneumatic operated device is disclosed in U.S. Pat. No. 5,392,681 to Hall disclosing an apparatus for changing the pitch of a drum by an annular distensible bladder in the form of a length of hose, containing air and having a valve connected to a pump. Thus, when air is pumped into the bladder, the bladder expands stretching the drum head over the shell. This device contains several serious flaws, including the annular distensible bladder which is actually not completely annular 360° about the drum head. Rather, it is a length of hose with one closed end and the other end connected to an optional feed line. However, to perform the task of tensioning a drum head in a completely uniform fashion, it is imperative the annular distensible bladder is one continuous member completely annular 360° about the drum head perimeter. This example fails to accomplish this necessary function. The bladder (or rather length of hose) in this device is incomplete and inconsistent in distensible cross-section at both ends in comparison to its body, which in use will apply inconsistent non-uniform tension to the drum head thereby rendering the intended function as flawed. A collection of components including an electric compressor, control valve, valve stem, pump, foot operated bellows, optional feed lines, control and bleed valves is listed as possible methods of controlling the device with no clear definition of actual method of operation for the device or alternative embodiments. The absence of a practical method of operation that is simple to install, quiet and easy to use in a musical production or performance setting renders this device impractical and unusable.
In view of the foregoing, percussionists and drummers are musicians who need a simple and practical acoustic drum head tuning system that accomplishes precise acoustic drum head tuning with ease, speed and musical versatility, producing clear resonant harmonic drum sound at any desired pitch. A drum head tuning system that installs easily on any conventional drum, will operate easily and silently while hidden from view, and must enhance creative musical drum sound.